The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
From DE 100 40 711 A1, a vane cell pump with a ring-shaped inner rotor is known, in which a plurality of vane elements extending radially outward are located radially moveable. The internal radial end parts of the vane elements rest on a torque proof central part, and the external radial end parts on a torque proof outer ring. The rotor can be rotated around a rotation axis that is offset with respect to the central axis of the central element and outer ring. This way, on rotation of the rotor between the vane elements, conveyor cells are formed that enlarge and then reduce again. By changing the volume of the conveyor cells, fluid is suctioned into the conveyor cells and subsequently expelled. The end parts of the vane elements slide on the central element and outer ring, respectively. Such a vane cell pump is simple and inexpensive to construct.
In order to increase the degree of efficiency, a vane cell machine in the form of a pendulum slide valve pump is known from DE 195 32 703 C1. In this pump, the vane elements are located moveable in an inner rotor, whereas they are supported pivotable in a ring-shaped outer rotor. The rotation axis of the inner rotor is offset in relation to the rotation axis of the outer rotor, so that during operation, conveyor cells form that likewise enlarge and subsequently reduce. But the pendulum slide valve pump known from DE 195 32 703 C1 is complex, and therefore expensive to construct.